When I was one-and-twentyI heard a wise man say,"Give crowns and pounds and guineasBut not your heart away;Give pearls away and rubiesBut keep your fancy free."But I was one-and-twenty,No use to talk to me.

The non-obvious words are:

crowns KROUPBS (actually, this is fairly straightforward)

pounds POUPBDZ (why DZ? I suppose DS is harder to chord)

guineas - Plover doesn't know the word "guinea". I could have typed it out manually, but I approximated it using the name of the country Guinea and making it plural: TKPWEU/TPHAOE/-S. What I think is interesting about this is that TKPWEU alone is "I go".

pearls PERLS (not much surprise there)

rubies - this is a tricky one. RAOU/PWEU/-S. And RAOU alone is "rue" like the herb.